Pressure-gage attachment.



WITNESSES Zkz 0M M W. A. ALLEN.

PRESSURE GAGE ATTACHMENT. APPLICATION FI LED NOV.25, 1911. RENEWED NOV. 6. I915.

Patented May 29, 19 17.

INVENTOR fikzaa'm id? M wrommm um earns ranr rric.

WILLIAM A. ALLEN, or YONKERS, NEW YORK, ASSIGNOR To A. SCI-IRADERS sON, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

PRESSURE-GAGE ATTACHMENT.

Specification of Letters Patent.

Patented May 29, 1917.

Application filed November 25, 1911, Serial NO. 662,287. Renewed Noyember 6, 1916. Serial N o. 129,893.

To all 'zekom, it may con/em.

Be it known that I, \VILIJAM' A. ALLnN, a citizen of the United States of America, and residing in the city of Yonkers, in the county of 'cstchester and State of New York,'ha\'e invented a certain new and useful Improvement in lressureGag: Attachments, of which the following is a specification.

My present lnventlou relates to an attachment for pressure gages by wluch an ordinary pressure gage commonly used for testing tires for automobiles, may be used for ascertaining the. compression of the ex: plosive mixture in the cylinder of an explosion engine.-

In the accompanying drawings,

Figure 1 is a side elevation of one form or pressure gage and attachment adjusted in position upon an engine cylinder;

Fig. 2 is an enlarged section of the same partly broken away;

Fig. 3 is a-plan of the attaching nut;

Figs. 4 and 5 are side elevations of-modified forms of the device.-

The cylinder of an explosion engine is commonly provided with a spark plug carried by a detachable nut, so that the. plug may be readily removed for cleansing or renewal. .In order to ascertaln the compression of the explosion gases in the cylinder the customary procedure is to remove the spark plug and to screw into its threaded aperture in the explosion cylinder a pressure gage device specially constructed for this purpose. This device is of a more or less expensive nature, and forms'an additional item of expense and care for the automobilist. I now propose to provide an attachment which may beinserted in the spark plug aperture and which is shaped to receive the attachment end of an ordlnary tire pressuregage, and preferably provided with means for holding thls gage 1n posl tion during a. test compression of the gases in the cylinder.

In the form shown in Figs. 1 to 3, I have illustrated a nut 10 with threaded shank 11, which is stepped to fit spark plug apertures of different diameters in the casing 12 of the explosion cylinder. A shoulderedv central bore 13 forms a passage for the gases from the cylinder 12 to the pressure gage 14 which is detachably mounted, on the nut by insertgage and ing the lower end of. the gage in an enlarged portion 16 of the here until it comes to rest against the washer 15 on the shoulder 17 within the nut. The washer 15 preventsthe escape of gases around the lower end of the gage, and insures their. entry into the gage at undiminished' pressure. To secure the gage in position during the test, it is suilicientthat it be-merely held down by hand against the washer, but I prefer to provide a latch 18 pivoted at 19 on the upper face of the nut and shaped to the curvature of the gage so that when the latch is swung into gage and thus retains the latter in position.

The tire gage illustrated being of the type shown in the Lyhne Patent No. 994,701, which is commonly provided with a thiinble 21 over which the latch 18 may readily catch to hold the gage in position in the nutlO, the gases in thec'ylinddr when put under compression, force out the. indicating sleeve 22 and the latter remains in indicating position upon the scale 23 after the cylinder has been exhausted.

In the modification illustrated in Fig. 4, the nut is provided with a central bore 24: of uniform diameter throughout its length, terminating in a slightly projecting nipple 25 on the upper face of the nut which on 'gage in position a pair of spring arms 27 are secured upon the upper face of the nut and are proyided with inwardly struck projections 28, which engage the shoulder 20 of the thimble'21 of the gage.

In the modification illustrated in Fig. 5, the construction is the same s in the modification just described, witli the exception that a spring device of diflerent character is employed to hold the ga e in adjusted position. For this purpose, have here shown a spring fork 29 secured on the upper face of the nut the legs of the fork straddling the overlying the shoulder 19 of the thimblein adjustedposition. To apply the gage to the nut in this construction, the lower end is positioned over the nipple 25 and the gage then swung up from the side.

Obviously the invention is not'limited to theparticular-type of gage illustrated nor,

face of the nut gagement with the upperendofthe thimble g a to the, particularforms of construction shown. 'Various'modific'ations of. the device will readily be su gested. The features of the invention whie '1 present themselves mostconspicuous'ly are the provision, ofa nutadapted V to be adjusted-in the, spark plug aperture of an explosion engine cylinder; a

seat on the nut forithe tire gage and,- preferably, meansfor holding the gage to'its seatduringthe test compression inthe -ey linder.

- '1 claim as my invent1on: v 4.

l. The coinbinationfof a pressnre gage having a thimble at its atta'ching-end,-w1tha nutexteriorly threaded to form a screw .connection' with a threaded aperture in, the V cylinder'of anexplosionengme, said nutbeing longitudinally perforated and having an internatshonldelf' toreceive a compressible washer, in combination with a washer on said shoulderagainst which the lower end of the nut, and

adapted t'o-be swung intoentemporarily to hold the gage temporarily in adjusted positionysubstantially as descr bed.

2. For use n'combinationwith apressure gage having athimble at its attaching end,

a new article of manufacture comprising a nntexteriorly threadedto fol-ma screw con- 1 in combination witlia' washeron saidshouh up ier surface oftheinut, together with, a.

.. latchon said ,nut' adapted to engage the upper end oi the thimble'iand holdthe gage tially as desei'ribeda' In testimony whereo nameto this. specification, inthe. presence of.

two subscribing witnesses. ofthe gage 1S pressed when the liippei edge oi? the thimble is flush with the upper surface a latch pivoted on the uppe1:

= l W LLiAMQgaLLENQ Witnesses:

. E; Genomeme,

finches ARQVENS.

": iection with atlireaded aperture in the -cyl-' finder of'an' explosion engine,

.der against which the lower end of the gage ispressed when-the thimble issflush with the 40 I111 adjnstediposition substan- I have signed 

